If King Tut's tomb hides a secret burial chamber, the mummy inside could belong to the elusive pharaoh Smenkhkare, or to queen Meritaton, the full or half sister of Tutankhamun, according to an international team of researchers.

Prompted by an inspection of King Tut's tomb last month by the Egyptian Antiquities Ministry, the new study discusses the likelihood of various missing royals who might be concealed in the 3,300-year-old tomb and rules out the hypothesis that queen Nefertiti, the most favored candidate, is buried there.

The investigation by the Egyptian authorities follows a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona. In July he published a paper arguing that high-resolution images of the tomb's walls show "distinct linear traces" pointing to the presence of two still unexplored chambers.

After the inspection last month, Egypt's Antiquities minister Mamdouh Eldamaty confirmed the likely presence of two hidden chambers behind the western and northern walls of the tomb.

"Based on these preliminary observations, the possible findings range from nothing at all or unfinished and closed corridors to storage chambers or intact burials with treasures,"mummy expert Frank Rühli, director of the Institute of Evolutionary Medicine at the University of Zurich, told Discovery News.

According to Reeves, one chamber contains the remains, and possibly the intact grave goods from queen Nefertiti, the wife of the "heretic" monotheistic pharaoh Akhenaten, Tutankhamun's father.

He argued that a painting located behind King Tut's sarcophagus has been wrongly interpreted. Egyptologists have always believed the scene shows Ay (who largely directed King Tut's reign and succeeded him)performing the Opening of the Mouth ritual on the boy king.

But Reeves offered a different reading: the figure labelled Tutankhamun is actually Nefertiti. He noted that a line at the side of the figure's mouth, called "oromental groove," is a trademark in pictures of Nefertiti. On the other hand, the figure labelled Ay would be Tutankhamun, completing the death ritual for Nefertiti.

Reeves speculated the tomb of King Tut was not ready when he died unexpectedly at age 19 in 1323 B.C. after having ruled a short reign of nine to 10 years. Thus he was buried in a rush in what was originally Nefertiti's tomb, who died 10 years earlier.

The "Younger Lady" is a mummy found in 1898 by archaeologist Victor Loret in tomb KV35 in the Valley of the Kings. The mummy lay adjacent to two other mummies, a young boy thought to be Webensenu or Prince Thutmose and an older woman, identified by recent DNA tests as Queen Tiye.

A controversial wall painting in King Tut's tomb displays a ritual called the Opening of the Mouth. |
Wikimedia Commons

In a study published on academia.edu, the same platform used by Reeves for his revolutionary paper downloaded more than 100.000 times within two months, Rühli and colleagues examine likely royal candidates for the potential hidden chamber.

"Chronological boundaries considerably shorten the list," they wrote.

They noted that Akhenaton died several years before. He was most likely buried in tomb TA 26 in Akhet-Aton in Middle Egypt, and might later have been transferred to the tomb known as KV55.

Rühli and colleagues also ruled out the other potential candidate, Queen Kiya, the mysterious secondary wife of Akhenaton who has been controversially debated to be King Tut's mother.

Her mummy has not been identified so far, but her canopic jars were apparently found in tomb KV55.

"This makes a separate burial in King Tut's tomb rather unlikely," Rühli said.

The researchers were left with enigmatic pharaoh Smenkhkare, whose true identity is quite uncertain. A possible predecessor of King Tut, Smenkhkare could be the royal hidden behind the walls of the most famous tomb in the Valley of the Kings.

"Any unclear new male mummy found in King Tut's tomb should be genetically tested whether he is a brother of the suggested Akhenaton and a son of Amenhotep III: both would be indicative of Smenkhkare," the researchers said.

On the contrary, if the mummy turns out to be a female, the name of Queen Meritaton should be considered.

The eldest daughter of Akhenaton and Nefertiti, Meritaton might have acted as a regent for her underage brother Tutankhamun.

"Her tomb is unknown, but some of her personal objects were apparently found among the burial items of King Tut," Rühli said.

Rühli and colleagues also stress that it is possible that nothing at all is found behind those walls and that any hypothesis about potential royal mummy candidates is very speculative at this stage.

A 1924 by photographer Harry Burton shows the unbroken seal of the third shrine which surrounded the sarcophagus of Tutankhamun. The double doors had been secured with elaborately tied ropes that bore clay seals.

"Tutankhamun: His Tomb and the Treasures" is a new exhibition now in Zurich that has meticulously reconstructed the tomb complex and its treasures. Specially trained craftspeople in Cairo built more than 1,000 exact replicas under scientific supervision. The work took over five years. Here is a replica of the famous mask of King Tut, weighing 24 lbs, which was pressed over the head of the king's bandaged mummy. The idealized portrait of the young king echoes the style of the late Amarna period. The life-like eyes are formed by bright quartz, with obsidian inlays for the pupils.

This scene, depicted on the backrest of King Tut's throne, shows how Tutankhamen used to lean back in a relaxed manner while his wife, Anchesenamun, stood beside him and rubbed ointment into his shoulder.

Tutankhamun's tomb and its contents, as viewed in a 3-D model. A corridor led to an antechamber and an annex filled with objects. The antechamber opened into the coffin chamber with King Tut's sarcophagus. The coffin chamber led to another small room filled with King Tut's treasures.

Two tiny mummified female fetuses were found in the tomb with the king. But they were not the only companions placed in the tomb for King Tut's journey to the afterlife. The boy king was buried with more than 5,000 priceless objects, including this treasure chest.

The dead king in the underworld was akin to the sun at night and, in the New Kingdom, this was identified with the god of death, Osiris. The heads of lions corresponded to the time the sun god spent in the body of the god of heaven in feline form. The facial details of the lion head –- the rims of the eyes, tip of the nose and tear ducts -- are given almost life-like properties through the use of glass.

These figures were supposed to take the place of the king in performing the daily tasks that came up in the afterlife. A total of 413 of these figures, known as ushabtis, were found in Tutankhamun's tomb. Among the collection, 365 were responsible for carrying out day-to-day duties, 36 ushabtis served as overseers for groups of 10 workers each, and 12 acted as monthly supervisors